A nonvolatile semiconductor memory having a floating gate can retain information even when power is turned off. Thus, it is mounted on many kinds of electronic devices. In such a nonvolatile semiconductor memory, it is important to control a thickness of an insulating film which covers the floating gate. For example, there is a method for forming a nonvolatile semiconductor memory by forming a capacitor insulating film and successively forming a conductive film (Reference 1: Japanese Patent Laid-Open No. 2004-140413).
As a memory element, one having an organic semiconductor has been developed (Reference 2: Japanese Patent Laid-Open No. 2004-47791). Reference 2 discloses a switching memory element which includes an organic semiconductor memory layer exhibiting a hysteresis characteristic and a semiconductor diode layer.